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Michael Erickson and Mike Root roped up at around 2 p.m. on May 13 to climb Miss Prissy (5.9+), a classic sport climb at the Jimmywood area of Foster Falls, near Chattanooga, Tennessee. Erickson, 22 climbed to the third bolt and prepared to clip it. Feeling out of position, he shifted his stance and his foot slipped. He plummeted past the second bolt and was suddenly wrenched sideways. He continued falling to the ground—about 40 feet in total—and landed on a rock, which drove into his ribs and the left side of his chest. Root, 27 quickly ascertained that his partner was alive, but in pain, and pulled out his cell phone to call 911. Erickson dissuaded him, however.

“By the time Mike pulled out his phone and was ready to call, I felt like I could at least get up,” he wrote us in an email. “It was scary as shit and hurt like hell. We thought about hiking out, but I elected to keep climbing since I didn’t want to be afraid of the wall.”

The two looked around and found a broken carabiner on the ground 25 feet away from the climb. It had broken off—sheared at the nose hook—at the second bolt.

Erickson continued climbing that day despite sore and bruised ribs. Less than a week later, he was back to normal.

ANALYSIS

In a blog entry a few weeks before Erickson’s accident, Kolin Powick, the director of global quality at Black Diamond, Inc., described a likely explanation for this carabiner failure.

“I’ve seen and/or heard of only a handful of carabiners that have broken in the field,” Powick wrote, “and most have broken in the same way-—nose-hooked. What is nose-hooked? It’s just like it sounds, the nose of the carabiner gets hung-up on a sling, Stopper wire or bolt hanger.”

Powick explained that while carabiners are very strong (a minimum of 4,496 pounds in a major—axis loading or 1,574 pounds in an open-gate loading), a nose-hooked carabiner can fail at less than 500 pounds, a force attainable even in a light bounce-test (dynamic loading).

The combination of an open-gate scenario with the cantilever causes an off-axis loading and excessive torque that results in a failure at low loads.

Mike Root sent his carabiner to Powick, who, based on the location of the break, concluded that the failure was due to a nose-hook scenario.

“Black Diamond tests a lot of carabiners,” Powick wrote in the same, earlier blog. “We not only understand the loads at which carabiners break, but also the … location of breakages … so it’s possible to look at where a carabiner is broken and have a good idea of how it was loaded. A nose-hooked carabiner will most often break at the top of the spine, while open- and closed-gate failures typically occur at the bottom of the spine, and minor-axis failures almost always occur at the gate.”

PREVENTION

When you’re engrossed in the moves of a climb, or negotiating a desperate clip, it is very easy to accidentally hook the nose of the carabiner and move past the improperly hung draw without noticing the flub. Sometimes you might rub the hung draw with your body or kick it as you pass, turning a properly hung quickdraw into a nose-hooked time bomb. The only prevention in these cases is awareness. Treat your quickdraw placements like natural protection. Visually inspect them and only move on when you know that they are properly oriented, with the sling aligned and both gates closed.

The surest way to prevent nose-hooking is to use carabiners that feature a “keylock” closure—picture a ball-and-socket joint with the ball on the gate and the socket on the nose. Because these biners have no notch on the nose that can snag bolt hangers, slings or wires, they virtually eliminate the risk of nose-hooking.

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